Cleaning and stripping device for coating-rollers



W. H. STHEEPER.

CLEANING AND STR APPLIC 1,331,463.

IPPING DEVICE FOR COATING ROLLEBS.

jammed Feb. 17, 1920.

UNITED ,sTATEs WILLIAM STREEPEB', OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO STOKESV AND1 SMITH COMPANY, OF PHILADELPHIA; PENNSYLVANIA; A CORPORATION 0F PENNSYLVANIA.

CLEANING AND STEIPPING DEVICE FOR COA'IINr-ROLILERS.

Specification of Letters Patent. I "Patented Feb, 17, 1920.

Application filed October 31, 1919. Serial No. 334,809.

To all who-m t may concern.'

Be it known that I, WILLIAM H. STREEPEE,

a citizen of the United States, and resident of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Cleaning and Stripping Devices for Coating-Rollers, of which the following is a specification.

This inventionvrelates to machines for applying a liquid coating to the surfn of sheet material, and particularly to ii -proved and simplified means for stripping the' sheet from a liquid'applying roll, and for promoting the even, uniform application of the coating to the sheet. l

In applying a coating of. liquid, suoli as glue, itis common practice to pass the sheet over a roller coated `with the liquid, the

natural tendency of the sheet to adhere to the roller being overcome by elements commonly known as strippers, which operate through the rotation ofthe roller to strip the sheet therefrom, usually serving also as guides to direct the coated sheet away from the roller.

To avoid crushing the advancing edge of so that the lrotationof the roller4 will cause the wiper to scrape all'surplus liquid out of the groove and maintain it clean and clear.

This is practically neceary when the liquid is glue or a similar substance which hardens rapidly, obstructing the groove and interferring substantially with the operation of the stripper and the eveness of the coating.

In one form of construction, the wiper projects into the groove at or adjacent to the point of tangency of the coating roller and a sheet, the coating roller may be provided.

with a circumferential groove, usually quite narrow, into which a portion of the stripper fits, enabling it to project under theforward sheet, and lift it with- `edge of the advancing out marring the edge.

To insure even application of the coating, it is likewise the usual practice to provide a separate dipping roller or wallower, which rotates in a tank of the coating liquid, transferring it to the grooved roller'either directly oi through intermediate transfer rollers. While this insures even distribu` tion of the liquid on the coating roller, which is pressed against the wallower, the liquor naturally tends to force itself into the grooves and collect on thestripper, causing an uneven distribution of the liquid onv the the wallower. able, as it prevents any substantial part of the glue from enteringthe groove.

- The uniform practice has been to have the stripper mounted on the frame of the machine, preferably adjustable so as to insure proper contact with the coating roller and engagement with the sheet. similarly mounted to engage the groove properly. It will be apparent, however, that The wiper is This constructionv is desirl the rotation of the coating roller exerts a certain amount of lateral stress on both the stripperand the wiper, necessitating a' rigid mounting. These elements, and particularly thewiper lare also subject to distortion and damage, as a slight variation in their mounting tends to cause them to engage the rolls,

andthe wiper may even be caught between the rotating rollers, seriously damaging the parts. Moreover, working conditions make it desirable to use relatively light, readily benda-blc material for these parts; and it has been found that they are liable to be bent in the exigencies of actual use. It is also necessary to adjust the parts with considerable care to insurefaccurate engagement with the groove and insu-re a minimum of friction on the sides and bottom of the groove, vet maintaining proper engagement therewith. This dificulty is particularly present when a plurality of grooves and groove en- 4gaging members is used, this construction requiring rigid and careful mounting.

To avoid this difficulty, and to eliminate both the construction of separate stripper and wiper elements and the necessity for a particularly rigid mounting of these elements, a combined stripper and wiper has been disclosed, acting as a unit and adapted to engage the coating roller at spaced points, 106 thus retaining both the stripper and wiper portions in accurate, even engagement with the roller, and avoiding unbalanced lateral sheet and a tendency to clog the roller adj acentV the stripper. f

To avoid this difficulty, it is the general practice to introduce a wiper or cleaning ele-y ment in each groove, operative through the rotation of the roller to prevent the accumulation of liquid in the groove. This wiper is preferably mounted in fixed position, and includes a portion extending into the groove avoiding the necessity for vertical adjust-u stresses on these elements, permitting. the use of a simple mounting, and entlrely ments of the separate elements.

The unitary structure, furthermore, permits the mounting of a plurality of strlpper and wiper units on a single carrier, with which they may have a slidable connection,

-as engagement of the elements with the grooves prevents motion in any direction,

and provides automatically the even and accurate engagement of both the stripper and the wiper with the sides and bottom of each groove.

Furthermore, the roller groove and the stripper and wiper have been so proportioned that the wiper fills the groove most effectively, the arrangement of parts positively preventing any accumulation or ridges of hardened coating material along the edges of the groove. f

The parts have also been arranged so that they may be very easily and cheaply stamped from sheet material, thus greatly simplifying and cheapening this part of the coating apparatus. v

Other objects and advantages of this invention will be apparent from the following description, taken in connection with line 2 2, Ilooking in the direction roller having a common form of automatic liquid applythe accompanying drawings, in which- Figure 1 is a transverse sectional view through a portion of a coating machine, showing the combined stripper and wiper in operative position,

Fig. 2 is a fragmentary view of the construction shown in Fig. 1, viewed from the of the arrows,

Fig. 3 is a fragmentary view of the construction shown in Fig. 1, viewed from line 3 3, looking in the direction of the arrow, showing the relation of the wiper to the groove, and

Fig. 4 is a perspective view-ofthe combined stripper and wiper.

This invention, is applicable to any type of apparatus for) applying a liquid coating which includes a rotating liquid applying periph/eral grooves; and while ing mechanism has been disclosed, it is to be understood that this is entirely illustrative, as the invention is equally suitable to liquid applying apparatus of various sorts, including hand-operated devices.

In the form illustrated, there is shown a liquid-containing reservoir 10 having a transverse dip ing roller or wallower 11 immersed in tlie liquid and tangent to a coating roller 12. A sheet of material 13 is fed by rollers 14 into contact with the coating roller 12 and partially around the latter, being held in engagement therewith by roller 15. After being stripped from the roller by means to be described hereinafter,

sheet 13 passes to delivery mechanism, such as endless belt 16.

The means for stripping sheet 13 from roller 12 includes a stripper finger 17, having a properly shaped toe 18 extending into circumferential groove 19 in roller l2. The end face 2O of stripper linger 17 is properly shaped to strip a sheet from the roller gradually to avoid marring or tearing of the sheet. Face 20 is also contoured adjacent its upper extremity 21 to direct a stripped sheet from the delivery mechanism. In the form disclosed, the sheet 13 is given a reverse turn to carry it on belt 16; but this is illustrative, as obviously face 20 might be contoured to direct the sheet at any angle from the surface of the roller to any suitable receiving means.

The wiper element 22 includesa downwardly projecting portion having a toe 23 adapted to it in groove 19. The point of engagement of toe 23 and groove 19 may obviously be varied, and this invention includes the location of the toe 23 at any point in the groove. In the preferred form, the toe is located in the groove at the point of tangency of roller 12 with roller 11, where the glue is transferred from the latter to thev former roller. "Ihis location is advantageous because it is much easier and more effective tof-prevent the initial entrance of the liquid into the groove 19 than it is to remove it after it is located therein.

It is also desirable to have toe 23 so proportioned that it substantially fills the entire groove 19, as is shown in Fig. 3, the toe 23 being shown somewhat spaced from the walls of the groove in .said figure merely for the sake of clearness. This insures perfect cleaning of the groove and consequent even performance of the coating operation. A further advantage of this .construction is that when rollers 12 and 11 have their axes in a plane inclined to the vertical, a temporary stoppage of the" rollers will cause a slight accumulation of glue behind roller 12, which otherwise would flow through the groove and back into the reservoir 10. This accumulation acts as an emergency supply wyhen the machine is again started.

It is also within the scope of this invention to locate the end of toe 23 at such a point relative to the line of tangency between rollers 11 and 12 that, while the body of groove 19 will be cleared of liquid, a film of the latter will be formed across the outer part of the narrow groove and will be applied to sheet 13, either before reaching toe `18 or by the action of the latter, thus avoidproperly proportioned and located to accomplish this result.

It will be apparent that while a single stripper and wiper unit has been described, a plurality thereof may be used in connection with a roller having a number of grooves; and the construction herein disclosed is particularly advantageous when so used, as the units are adapted to be mounted upon a single carrier, such as rod Q1, without the necessity for individual adjustment. In this connection, it will be apparent that with rod 24 in ixed position and the units loosely mounted thereon, each unit. is practically self adjusting, as the pressure of lthe stripper linger on 'the bottom of the groove is equalized b-y the pressure of wiper 22 on said bottom, and the pressure of said elements against the sides of the groove is necessarily equa-l, as greater friction on one side would tend to shift the unit toward the other. This action is predicated upon a mounting such as that disclosed, in which the unit is free to rotate and slide upon its mounting element; but it will be apparent that the invention is not necessarily limited to such a construction, and the unit may be mounted rigidly or may have a rigid mounting element with the roll-engaging members of the unit movably connected thereto.

While the stripper linger 17 and wiper 22 may be separately constructed and connected together either rigidly or by spring connections, or otherwise, such constructions being integral in the broad sense of the word as used in the claims, in the preferred form the elements are constructed in a single piece, either by `casting or by stamping from sheet material, or in any other way. In any event, both the stripper 17 and the wiper 2Q are connected to a single carrying element, shown in the drawings as hub 25, so that the entire structure is a unit. It will be apparent that when the stripper andwiper are stamped from a single sheet of metal, the mounting element will consist of the con necting part adjacent the sections of hub 25, which may also be stamped from sheet metal and attached to the combined stripper and wiper, or which if desired, may be omitted altogether.

IVhile a preferred form of this invention and certain modifications thereof have been described, it will be apparent that many other changes may 'be made within the spirit of the invention as set forth in this specication.

I claim:

1. In an apparatus for coating sheet material with liquid and having a coating roller provided with a circumferential groove, means for stripping a sheet from said roller, and means integral with said stripping means for removing excess of liquid from the groove.

2.l In an apparatus for coating sheet material with liquid and having a coating roller provided with a circumferential groove, means for stripping a sheet from the roller including an element. projecting into the groove adapted to `direct a sheet away from the roller when the latter is rotated, and means integral with said stripping means and having a portion extending into the groove to remove surplus liquid therefrom.

3. In an apparatus for coating sheet material with liquid and having a coating roller provided with a circumferential groove, means for stripping a sheet from the roller including an element projecting into the groove adapted to direct a sheet away from the roller when the latter is rotated, and means integral with said stripping means having a portion extending into and sub stantially filling the groove to remove surplus liquid therefrom. y

4. In an apparatus for coating sheet Inaterial with liquid and having a coating roller provided with a circumferential groove, means for stripping a sheet from said roller including a porticn'located in the groove, means for removing surplus liquid from the groove including a portion extending into said groove, and an element connecting said stripping and liquid removing means and maintaining them in predetermined relation to each other, whereby they may be mounted and operated as a unit.

5. In an apparatus for coating sheet material with liquid and having a coating roller provided with a circumferential groove, means for stripping a sheet from the roller including a portion extending into the groove, means for removing surplus liquid from the groove including a portion extending into said groove, and means for rigidly connecting said stripping and liquid removing means directly to each other to form a unitary structure.

6. In an apparatus for coating sheet material with liquid and having a coating roller provided with a circumferential groove and liquid carrying means tangent to said roller and adapted to transfer liquid thereto, means for stripping a sheet from the roller including a portion extending into the groove, and means for removing surplus liquid from the groove including a portion extending into the groove adjacent the line of tangency of the roller and the liquid carrying means, said liquid removing means and stripping means being directly connected to each other to form a unitary structure.

7. In an apparatus for coating sheet material with liquid and having a coating roller provided with a circumferential groove and liquid carrying means` tangent to said roller and adapted to transfer liquid thereto, means for stripping -a sheet from the roller loo including a portion extending into the groove, and means for removing surplus liquid from the groove including a portion extending into and substantially filling the groove adjacent the line of tangency of the roller and the liquid carrying means, said liquid removing and stripping means being directly connected to each other to form a unitary structure. p

8. In an apparatus for coating 'sheet material with liquid and having a coating roller provided with a circumferential groove, means for strip ing a sheet from said roller, means for removing excess of liquid from the groove, a carrymg element upon Which said stripping means and liquid removing means are mounted to form a unitary struc-v ture, and a support upon which said carrying element 1s shdably mounted.

9. ln an apparatus for coating sheet material with liquid and having a coating roller provided With a circumferential groove, means for stripping a sheet from said roller, means for removing excess of liquid from the groove, a carrying element upon Which said stripping means and liquid removing means are mounted to form a unitary structure, and a support upon Which said carrying element is slidably and rotatably mounted.

Signed at Philadelphia, in the county of Philadelphia and 'State of Pennsylvania, this 23rd day of Oct., A. D. 1919.

- WILLIAM H. STREEPER. 

